HELP! 2002 GMC Yukon SLT Fuel sensor/ABS Brake light/ radio

[joelbattle]

Hi, my 2002 GMC Yukon popped an engine light today and the codes were P0179 and P0178. Both have to do with the flex fuel Sensor, but I have no idea how to take it apart or test it. Any ideas? Also my ABS and Brake light came on simultaneously while driving, goes away when I restart the vehicle, but comes back on after a few minutes of driving. Also the radio display will sometimes not work, but the radio will still come on and play music- just no display.. sometimes it works, sometimes it doesnt... Just dont know where to start. any help appreciated..thanks.

 

[OR VietVet]

Welcome to the forum from Oregon.

With all these codes/problems seeming to be related with electrical problems, unless of course you do have a failing flex fuel sensor, I would be worried about the grounds that these rigs have known problems with. Here is a link to read about that: https://www.fixmyoldride.com/Chevro...e7e5cd24ed24635&at_ab=per-2&at_pos=3&at_tot=4

The brake light and abs light could be a problem with the front wheel hubs and/or the sensors and wiring to them. Again, another well known symptom.

I also suggest you check out several you tube videos about these concerns. I say several because lots of the you tube videos are crap and if you only view one, you may see a crap video.

 

[Fless]

For the FF sensor here is some basic troubleshooting. This can confirm that the sensor is getting the right electrical signals. If it passes the initial voltage tests, then the frequency test is indicated.

https://ricksfreeautorepairadvice.com/p0179-gm-vehicles/

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics, please.

You are already receiving suggestions from the folks here, and others will chime in.

Be sure to check all ground connections in the engine compartment, to ensure that they are clean and tight. Deteriorated ground connections are common on these trucks, and they will raise Hell with the truck's electrical systems.

 

[treehan77]

In my experience, ABS and brake light coming on like that is usually a bad solder joint in the ABS computer. They’re expensive, but you can get one fairly cheap from a salvage yard OR just retouch all the solder joints! That fixed it for me for free.

 

[Rocket Man]

For the ABS, you need to get the codes scanned. An auto parts store should be able to do that or a code reader that will read ABS. It could be several things including one of the wheel speed sensors.